Progressive failure and scale effect of anchor foundations in sand

Abstract

Progressive failure is considered one of the least understood classical problems in geomechanics, gaining considerable attention in foundation related problems. However, the transformation of model test results to prototype is so much complex (scale effect). This paper highlights a FE ideology for evaluation of the response of shallow circular anchor foundations in sands with sophisticated strain hardening-softening behaviour. In these soils, the progressive failure can occur because of the non-mobilization of pinnacle strength of soil on potential failure surface and softening behaviour of soils. The presented paradigm allows this failure phenomenon to be properly evaluated by using a non-associated elastoplastic constitutive model coupled with explicit dynamic relaxation method considering yield surface as the MC material model and the potential surface is the smooth DP model having shear band effect. The FE results are compared with experimental outcomes to assess the reliability. Numerical model well-predicted the experimental stress-strain data points from element tests very closely. The scale effect is deliberated due to the progressive failure with shear banding phenomenon, which is remarkable with the increase of embedment and predominant in the sand of higher density. The peak resistance factor and settlement are presenting a decreasing trend with the increase of foundation width.